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Space


SL-6 A-2-e Molniya Launch Vehicle

The A-2 version was itself a step back from the A-2-e. In this version, there was indeed a seventh engine, in contrast to Voskhod and Soyuz. This added stage when used is contained within the shroud which covers the payload. The Russians after Luna 3 used consistently a special technique for their flights which required an extra stage. This was especially important for flights more nearly in the plane of the equator, since the Soviet launch sites are at relatively northern latitudes. The rocket assembly is launched from the cosmodrome to place the interplanetary larger stage plus the payload in low circular Earth orbit, where the burned out stage is separated. During the course of the first orbit as the payload heads northeast across the South Atlantic to cross Africa, a special orbital launch platform, never specifically described as to shape, dimensions, or weight, is oriented and from it the final payload is launched to higher speed by the escape rocket. This probe rocket, after it has done its work, is separated from the payload and flies on essentially the path as the payload.

It had not been described in detail in Soviet publications available in the West. However, it was shown diagrammatically in a Soviet pamphlet written in German, "Nachrich-tenbriike in Kosmos" which described Molniya 1. This has subsequently been issued in English: "A Satellite's Overhead". The stage is shown as a stubby cylinder measuring about 2 meters in diameter and perhaps 2.5 meters long. The Royal Aircraft Establishment estimates its length as 2 meters. Soviet payloads which are launched from the orbital launch platforms and given their impetus with this added escape stage also carry a special maneuvering engine for orbit adjustments and smaller verniers for orientation.

When this whole system works, it does a very effective job. The Soviet program is given added flexibility as to launch windows through the technique of orbital launch, and calculations can be made as to the final stage firing in the relative tranquility of the vacuum of space. This flexibility is important for the Russians who have lacked the worldwide network of land-based tracking and control stations which the United States has developed in cooperation with other nations. But the number of steps required to carry out a deep space mission, supported by automatic devices and a few ships, tended to expose these operations to a fairly high failure rate.

Assuming that in general Soviet flight successes and failures are comparable to those of the United States because competent people in both countries are applying the same technology, then we see no particular reason why Soviet Earth orbital operations should be any less successful than those of the United States . But deep space work with the platform launch technique presents in fact another story. For example, the United States has made 59 launch attempts for escape missions, of which only 11, or 19 percent, have failed to escape. The Soviet Union has made an unpublished number of attempts to use the orbital launch technique, but we can note that of 65 Earth orbiting platforms carrying payloads intended for the Moon, Mars, or Venus, 20 failed to send their probe payloads beyond Earth orbit, or a failure rate of 31 percent, higher than the U.S. rate. The total failure rate is undoubtedly higher for deep space missions because additional flights presumably did not even attain Earth orbit.

References:

1. SOVIET SPACE PROGRAMS, 1971-75, OVERVIEW, FACILITIES AND HARDWARE MANNED AND UNMANNED FLIGHT PROGRAMS, BIOASTRONAUTICS CIVIL AND MILITARY APPLICATIONS PROJECTIONS OF FUTURE PLANS, STAFF REPORT , THE COMMITTEE ON AERONAUTICAL AND SPACE .SCIENCES, UNITED STATES SENATE, BY THE SCIENCE POLICY RESEARCH DIVISION CONGRESSIONAL RESEARCH SERVICE, THE LIBRARY OF CONGRESS, VOLUME – I, AUGUST 30, 1976, GOVERNMENT PRINTING OFFICE, WASHINGTON : 1976,

15. Vladimirov, Leonid. The Russian Space Bluff, London : Tom Stacey Ltd., 1971, p. 83.

Molniya

Background Information
First Launch:
February 1961
Flight Rate:
12 per year (maximum recorded launch rate)
Launch Site:
Plesetsk and Baikonur, Russia
Capability:
3,564 lb lunar delivery trajectory;
2,596 lb Venus delivery trajectory;
2,090 lb Mars delivery trajectory

History

  • Developed from the Vostok and Soyuz launch vehicles originally derived from the SS-6 ICBM
  • Includes a third stage for high-energy interplanetary missions
  • Used to launch many of the former Soviet Union's early interplanetary space probes

Description

  • Three-stage liquid fueled vehicle
  • Stage 1 core has one RD-108 booster engine (one turbo pump with four separate combustion chambers) burning LO2/kerosene propellant fed from stage 1 tanks, generating 167,000 lb of thrust
  • Stage 1 strap-ons each have one RD-107 engine (one turbo pump with four separate combustion chambers) burning LO2/kerosene propellant fed from stage 1 tank, generating a total of 740,000 lb of thrust
  • Stage 2 has one RD-461 engine burning LO2/kerosene, generating 67,000 lb of thrust
  • Stage 3 engine burns LO2/kerosene, generating 15,000 lb of thrust

Profile

Length:
138 ft
Launch Weight:
683,000 lb
Diameter
8.9 ft
Liftoff Thrust:
907,000 lb
Payload Fairing:
12.1 ft x 7.6 ft




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Page last modified: 03-06-2018 19:18:01 ZULU